it is definatley worth having the new owner contact the gown manufacturer to see if the dress were paid for. Unfortunately it sounds kind of shady and the old owner probably skipped with the cash. I truly hope that the girls paid with credit cards, dispute those charges right away. It would be in the new owner's best interest to try to work with you, not just say sorry out of luck. That is really not good business practices. You might have some legal recourse